Conventional wiring systems include large circuit breaker panels from which wires for electrical circuits are routed to smaller electrical boxes that may be nailed between the studs and joists of a house, office building or other structure to provide electrical power at various locations in each room of the structure. Then, electrical switches, dual outlet receptacles, wiring junctions and other functional circuit assemblies are mounted in these small electrical boxes and connected to wires of electrical circuits within the structure.
To attach an electrical wire to a conventional function assembly, the electrical wire is passed through an opening in the box, the end of the wire is stripped of its insulation, and then the stripped end is bent around a screw of an assembly contact and secured into place by tightening the screw. The functional assembly is then pushed back into the box where it is retained by passing screws through a flange of the assembly and into a corresponding flange of the box. Similarly, where a conventional box is used to form a junction between input and output electrical wires, the respective wires may be inserted into the box through opposing openings in the sides thereof, then pulled out, stripped and twisted together by means of wire nuts, and then pushed back into the box so as to be secured therein by a cover.
In order to change a previously installed switch, outlet or other assembly in a conventional box, it is necessary to remove the box cover, then pull out the old assembly with the wires attached thereto, then detach the wires from the old assembly and reattach them to the new assembly, and then push the new assembly back in the box and secure it therein as previously described. During this changing of assemblies, the power to the box must be turned off in order to avoid the possibility of an electrical shock should the installer inadvertently touch a live wire or component that is exposed during the changing process.